“The fertilized cell is quite another thing from the unfertilized cell. For if we must regard the spermia [spermatozoä] as real cells, no less than the ova, and the process of conception as the coälescence of the two we must consider the resultant cell as a quite new and independent organism. It bears in the cell and nuclear matter of the penetrating spermatozoön a part of the father’s body, and in the protoplasm of the ovum a part of the mother’s body. This is clear from the fact that the child inherits many features from both parents. It inherits from the father by means of the spermatozoön and from the mother by means of the ovum. The actual blending of the two cells produces a third cell, which is the germ of the child, or new organism conceived. One may also say of this sexual coälescence that _the stem cell is a simple hermaphrodite_, it unites both sexual substances in itself.” (Ev. Man, pp. 53-54.) “The individual development,” he says, “in man and the other animals, commences with the formation of a simple ‘stem-cell,’ of this character, and this then passes by repeated segmentation (or cleavage) into a cluster of cells, known as ‘the segmentation sphere,’ or ‘segmentation cell.’” (Haeckel, Ev. Man, p. 54.) On another page (56) he says: “Hence the essential point in the process of sexual reproduction or impregnation is the formation of a new cell, the stem-cell, by the combination of two originally different cells, the female ovum and the male spermatozoön. The process is of the highest importance and merits our closest attention. All that happens in the later development of this first cell, and in the life of the organism that comes of it, is determined from the first by the chemical and morphological composition of the stem-cell, its nucleus and its body.” (Ev. Man, p. 56.) “Hertwig,” he continues, “puts his theory of conception thus: ‘Conception consists in the copulation of two cell-nuclei, which comes from a male and a female cell.…’ “As the phenomenon of heredity is inseparably connected with the reproductive process we may further conclude that these two copulating nuclei convey the characteristics which are transmitted from parents to offspring.” (Ev. of Man, p. 56.) “As, moreover, there is a complete coälescence (fusion) of the mutually attracted nuclear substances in conception, and the new nucleus formed (the stem nucleus) is the real starting point for the development of the fresh organism, the further conclusion may be drawn that the male nucleus conveys to the child the qualities of the father, and the female nucleus the features of the mother.